index.test.js

const {
  placeholderGenerator,
  where,
  sql,
  limit,
  offset,
  and,
  or
} = require("./index")

describe("placeholderGenerator.gen", () => {
  it("should return placeholder", () => {
    const $ = placeholderGenerator()
    expect($.gen('a')).toEqual('$1')
    expect($.gen('b')).toEqual('$2')
  })
})

describe("placeholderGenerator.getValues", () => {
  it("should return values", () => {
    const $ = placeholderGenerator()
    $.gen('a')
    $.gen('b')

    expect($.getValues()).toEqual(['a', 'b'])
  })
})

describe("where", () => {
  it("works", () => {
    const $ = placeholderGenerator()
    const params = {
      name: 'aname',
      id: ['aid', 'bid'],
      date: undefined
    }
    const got = where(
      and(
        ['name =', params.name],
        or(
          ['id IN', params.id],
          "address = 'somewhere'"
        ),
        ['date =', params.date],
        () => {
          return "category like 'hoooman'"
        }
      )
    )($.gen)
    const expected = "WHERE ( name = $1 AND ( id IN ( $2, $3 ) OR address = 'somewhere' ) AND category like 'hoooman' )"
    expect(got).toEqual(expected)
    expect($.getValues()).toEqual(['aname', 'aid', 'bid'])
  })
})

describe("sql", () => {
  it("works", () => {
    const params = {
      id: 1,
      name: 'apple',
      limit: 10,
      offset: 20
    }
    const result = sql`
    SELECT * FROM users
    ${where(
      and(
        ['id =', params.id],
        ['name like', params.name],
        ['location =', params.location]
      )
    )}
    ${limit(params.limit)}
    ${offset(params.offset)};
    `

    const expectedSql = `
    SELECT * FROM users
    WHERE ( id = $1 AND name like $2 )
    LIMIT $3
    OFFSET $4;
    `
    const expected = [expectedSql, [1, "apple", 10, 20]]
    expect(result).toEqual(expected)
  })
})

describe("limit", () => {
  it("works", () => {
    const $ = placeholderGenerator()
    const params = {
      limit: 10
    }
    const expected = 'LIMIT $1'
    const got = limit(params.limit)($.gen)
    expect(got).toEqual(expected)
    expect($.getValues()).toEqual([params.limit])
  })

  it("returns empty string if falsy value is passed", () => {
    const $ = placeholderGenerator()
    const expected = ''

    const got1 = limit(undefined)($.gen)
    expect(got1).toEqual('')

    const got2 = limit(null)($.gen)
    expect(got2).toEqual('')

    const got3 = limit(0)($.gen)
    expect(got3).toEqual('')

    const got4 = limit(false)($.gen)
    expect(got4).toEqual('')
  })
})

describe("offset", () => {
  it("works", () => {
    const $ = placeholderGenerator()
    const params = {
      offset: 50
    }
    const expected = 'OFFSET $1'
    const got = offset(params.offset)($.gen)
    expect(got).toEqual(expected)
    expect($.getValues()).toEqual([params.offset])
  })

  it("returns empty string if falsy value is passed", () => {
    const $ = placeholderGenerator()
    const expected = ''

    const got1 = offset(undefined)($.gen)
    expect(got1).toEqual('')

    const got2 = offset(null)($.gen)
    expect(got2).toEqual('')

    const got3 = offset(0)($.gen)
    expect(got3).toEqual('')

    const got4 = offset(false)($.gen)
    expect(got4).toEqual('')
  })
})